DESCRIPTION: (provided by the applicant) Our research goal is to develop and validate miniature impedance sensors which can quantify the osseointegration of dental and other implants nondestructively in vivo, from the time of placement onward. We have demonstrated that mechanical impedance correlates with clinical and histologic measures of osseointegration, and that a self-contained sensor/actuator package can detect time-varying impedance. We now propose using micro-electromechanical systems (MEMS) technology to construct miniaturized impedance instruments which, encapsulated within implants and placed in dog mandibles, will yield noninvasive measurements during the healing and osseointegration process. The implantable impedance-based osseointegration sensor (IIOS) offers a new and improved way to observe, study, predict, and enhance the osseointegration process. Originally conceived for dental implants, the principle can also be applied to other implants, tissues, or engineering structures. Our aims comprise four tasks: (1) design and construct an implantable prototype using MEMS technology; (2) employ the prototype in vivo to characterize early-stage osseointegration; (3) conduct engineering studies of pivotal technical issues; and (4) design a human-qualified system for clinical research. This continues a collaboration with the University of Alabama, Birmingham, and the University of California, Berkeley. PROPOSED COMMERCIAL APPLICATION: A disposable, minimally invasive instrument for continuous measurement of the mechanical impedance (rigidity) of biological structures, with applications to: progressive osseointegration of dental implants; stability of other implants and biomimetic devices; feedback of muscle tone and tension for functional electrical (neuromuscular) stimultion. Also significant applications to nondestructive monitoring of tension, integrity, or stability of non-biological structures.